update.yml

name: Update
on:
  # Runs everyday at noon
  schedule:
    - cron: "0 12 * * *"
  # Allow manual triggering
  workflow_dispatch:
    inputs:
      lock:
        type: boolean
        default: true
        description: Update flake.lock
      generate:
        type: boolean
        default: true
        description: Update generated files
      check_for_changes:
        type: boolean
        default: false
        description: Cancel if there are no changes to the `nixpkgs` input

# Allow one concurrent update per branch
concurrency:
  group: "update-${{ github.ref_name }}"
  cancel-in-progress: true

# Allow pushing and creating PRs
permissions:
  contents: write
  pull-requests: write

jobs:
  update:
    name: Update the flake inputs and generate options
    runs-on: ubuntu-latest
    timeout-minutes: 40
    if: github.event_name != 'schedule' || github.repository == 'nix-community/nixvim'
    env:
      repo: ${{ github.repository }}
      base_branch: ${{ github.ref_name }}
      pr_branch: update/${{ github.ref_name }}
      team: nix-community/nixvim

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          ssh-key: ${{ secrets.CI_UPDATE_SSH_KEY }}

      - name: Install Nix
        uses: cachix/install-nix-action@v30
        with:
          nix_path: nixpkgs=channel:nixos-unstable
          github_access_token: ${{ secrets.GITHUB_TOKEN }}

      - name: Configure git
        run: |
          git config user.name 'github-actions[bot]'
          git config user.email '41898282+github-actions[bot]@users.noreply.github.com'

      - name: Create update branch
        run: |
          git branch -D "$pr_branch" || echo "Nothing to delete"
          git switch -c "$pr_branch"

      - name: Get info on the current PR
        id: open_pr_info
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          # Query for info about the already open update PR
          info=$(
            gh api graphql -F owner='{owner}' -F repo='{repo}' -F branch="$pr_branch" -f query='
              query($owner:String!, $repo:String!, $branch:String!) {
                repository(owner: $owner, name: $repo) {
                  pullRequests(first: 1, states: OPEN, headRefName: $branch) {
                    nodes {
                      number
                      url
                    }
                  }
                }
              }
            ' | jq --raw-output '
              .data.repository.pullRequests.nodes[]
              | to_entries[]
              | "\(.key)=\(.value)"
            '
          )
          if [[ -n "$info" ]]; then
            echo "PR info:"
            echo "$info"
            echo "$info" >> $GITHUB_OUTPUT
          else
            echo "No PR is currently open"
          fi

      - name: Update flake.lock
        id: flake_lock
        if: inputs.lock || github.event_name == 'schedule'
        run: |
          old=$(git show --no-patch --format=%h)
          nix flake update --commit-lock-file
          new=$(git show --no-patch --format=%h)
          if [ "$old" != "$new" ]; then
            echo "body<<EOF" >> "$GITHUB_OUTPUT"
            git show --no-patch --format=%b >> "$GITHUB_OUTPUT"
            echo "EOF" >> "$GITHUB_OUTPUT"
          fi

      - name: Check if nixpkgs input was changed
        id: changes
        if: github.event_name == 'schedule' || inputs.check_for_changes
        env:
          pr_num: ${{ steps.open_pr_info.outputs.number }}
          pr_url: ${{ steps.open_pr_info.outputs.url }}
        run: |
          getAttr() {
            nix eval --raw --impure \
              --expr '{ ref }: builtins.getFlake ref' \
              --argstr ref "$1" "$2"
          }
          getNixpkgsRev() {
            getAttr "$1" 'inputs.nixpkgs.rev'
          }

          if [[ -n "$pr_num" ]]; then
            old_branch=$pr_branch
          else
            old_branch=$base_branch
          fi
          old=$(getNixpkgsRev "github:$repo/$old_branch")
          new=$(getNixpkgsRev "$PWD")

          (
            echo "old_rev=$old"
            echo "new_rev=$new"
          ) >> $GITHUB_OUTPUT

          if [[ "$old" = "$new" ]]; then
            echo "Old and new revisions are the same"
            echo 'cancelled=1' >> $GITHUB_OUTPUT
          else
            echo "Old and new revisions are different"
          fi

      - name: Update generated files
        id: generate
        if: (!steps.changes.outputs.cancelled) && (inputs.generate || github.event_name == 'schedule')
        run: |
          old=$(git show --no-patch --format=%h)
          nix-build ./update-scripts -A generate
          ./result/bin/generate --commit
          new=$(git show --no-patch --format=%h)
          if [ "$old" != "$new" ]; then
            body=$(git show --no-patch --format=%b)
            echo "body<<EOF" >> "$GITHUB_OUTPUT"
            if [ -n "$body" ]; then
              # Multi-file changes are listed in the body
              echo "$body" >> "$GITHUB_OUTPUT"
            else
              # Single-file changes are only in the summary,
              # e.g. "generated: Updated none-ls.nix"
              git show --no-patch --format=%s | \
              sed -e 's/^generated:/-/' >> "$GITHUB_OUTPUT"
            fi
            echo "EOF" >> "$GITHUB_OUTPUT"
          fi

      - name: Create or Update Pull Request
        id: updated_pr
        if: (!steps.changes.outputs.cancelled)
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          title: |
            [${{ github.ref_name }}] Update flake.lock & generated files
          body: |
            ## Flake lockfile
            ```
            ${{ steps.flake_lock.outputs.body || 'No changes' }}
            ```

            ## Generate
            ${{ steps.generate.outputs.body || 'No changes' }}
        run: |
          # TODO:
          # - cherry-pick additional commits from already open PR
          # - avoid pushing if there are no changes
          echo "Pushing to remote branch $pr_branch"
          git push --force --set-upstream origin "$pr_branch"

          if [[ -n "$pr_num" ]]; then
            echo "Editing existing PR #$pr_num"
            operation=updated
            gh pr edit "$pr_num" \
              --body "$body" \
              --add-reviewer "$team"
          else
            echo "Creating new PR"
            operation=created
            gh pr create \
              --base "$base_branch" \
              --title "$title" \
              --body "$body" \
              --reviewer "$team"
          fi

          pr_info=$(
            # Get info from `gh pr view`
            gh pr view --json 'headRefName,number,url' --jq '
              to_entries[]
              | .key |=
                  # Rename headRefName -> branch
                  if . == "headRefName" then "branch"
                  else . end
              | "\(.key)=\(.value)"
            '
            # Get additional info locally
            echo "head=$(git rev-parse HEAD)"
            echo "operation=$operation"
          )
          echo "PR Info:"
          echo "$pr_info"
          echo "$pr_info" >> $GITHUB_OUTPUT

      - name: Print summary
        if: steps.updated_pr.outputs.number
        env:
          pr_num: ${{ steps.updated_pr.outputs.number }}
          pr_url: ${{ steps.updated_pr.outputs.url }}
          pr_branch: ${{ steps.updated_pr.outputs.branch }}
          head: ${{ steps.updated_pr.outputs.head }}
          operation: ${{ steps.updated_pr.outputs.operation }}
        run: |
          short=${head:0:6}
          # stdout
          echo "${short} pushed to ${pr_branch}"
          echo "#${pr_num} was ${operation}: ${pr_url}"
          ( # markdown summary
            echo "## ${{ github.ref_name }}"
            echo
            echo "\`${short}\` pushed to \`${pr_branch}\`"
            echo
            echo "[#${pr_num}](${pr_url}) was ${operation}."
            echo
          ) >> $GITHUB_STEP_SUMMARY

      - name: Print cancellation summary
        if: (!steps.updated_pr.outputs.number)
        env:
          pr_num: ${{ steps.open_pr_info.outputs.number }}
          pr_url: ${{ steps.open_pr_info.outputs.url }}
          changes: ${{ steps.flake_lock.outputs.body || 'No changes' }}
          cancelled: ${{ steps.changes.outputs.cancelled || '' }}
          rev: ${{ steps.changes.outputs.new_rev || '' }}
        run: |
          if [[ -n "$cancelled" ]]; then
            ( # stdout
              echo "nixpkgs rev has not changed ($rev)."
              echo 'You can re-run the workflow manually to update anyway.'
            ) >&2
            ( # markdown summary
              echo '## Update cancelled'
              echo
              if [[ -n "$pr_num" ]]; then
                echo -n 'The `nixpkgs` input has not changed compared to the already open PR: '
                echo "[#$pr_num]($pr_url) (\`nixpkgs.rev: ${rev:0:6}\`)."
              else
                echo -n 'The `nixpkgs` input has not changed compared to the base branch: '
                echo "\`$base_branch\`"
              fi
              echo
              echo 'You can re-run the workflow manually to update anyway.'
              echo
            ) >> $GITHUB_STEP_SUMMARY
          else
            ( #stdout
              echo "No PR was opened"
            ) >&2
            (
              echo "## Not updated"
              echo
            ) >> $GITHUB_STEP_SUMMARY
          fi
          ( # markdown summary
            echo
            echo 'The following changes would have been made:'
            echo
            echo '```'
            echo "$changes"
            echo '```'
            echo
          ) >> $GITHUB_STEP_SUMMARY